Example The sum of the numerator and denominator of a fraction is 11. If 1 is subtracted from he numerator and 2 is added to the denominator then the value of fraction. Find the fraction.

Though you are looking for the fraction, you can not assume the fraction as 'x ', (note this).

Letting the numerator be 'x'. By using the phrase ’the sum of numerator and denominator is 11’ gives us

The denominator = (11 - x )

\ The fraction =

Setting the equation as -

If 1 is subtracted from numerator and 2 is added to the denominator, then the value of fraction is

By cross multiplying, we get

3 ( x- 1) = 1 ( 13 - x )

3 x - 3 = 13 - x

\ 3 x + x = 13 + 3 . . . ( on transposing )

\ 4 x = 16

\ x = 4

Therefore, the required fraction =

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Index

9.1 - Definition and Solving Techniques
9.2 - Use of Simultaneous Linear Equations

Chapter 1